Combined drill and marking device



June 8, 1954 N. B. HIRSCHFELD 2,680,254 COMBINED DRILL AND MARKINGDEVICE Filed March 27, 1952 FIG. 2. FIG. l.

26 I I I /3 17 FIG. 5

A m I 77/ N 5. 27152 532 5412 the upper face being so Patented June 8,1954 UNITED STATES PATENT OFFICE 2,680,254 COMBINED DRILL AND MARKINGDEVICE Nathan B. Hirschfeld, New York, N. Y. Application March 27, 1952,Serial No. 278,923

6 Claims.

My invention relates to an improved combined drilling and marking devicewhich is particularly suitable for use in carpentry.

In carpentry, it is common practice to secure two pieces of woodtogether by placing dowel pins in alined holes of the respective pieces.The holes must be placed accurately in order to ensure proper alinement.In one method a hole is first drilled to a specified depth inthe firstpiece, and a temporary marking element of a length corresponding to thedepth of the hole is inserted therein. The second piece is then placedin the desired position of registration with the first piece, so thatthe marking element marks the spot on the second piece for thec0rresponding hole. It is important for accurate work that the firsthole be drilled to exactly the proper depth corresponding to the lengthof the marking element. However, because of the presence of wood chipsand wood dust in the hole, it is uncertain that the marking element willbe located precisely as desired relative to the surface of the firstpiece when inserted in the hole, even though the hole was initiallydrilled to the proper depth.

My improved device comprises a separable drill chuck and drill bit, thebit also serving as the marking element and the chuck carrying anadjustable collar to ensure that the hole will be of the proper depthrelative to the marking element.

The bit has a threaded recess in its upper face, cut that only acircular rim remains. A marking element having an upstanding point islocated in the recess and is co-axial therewith. The chuck has athreaded extension which may be screwed into the recess, said extensionhaving a further recess which receives the marking element. The collaris adjusted on the chuck so that when it strikes the piece of Wood beingdrilled, thereby stopping the drilling, the point of the marking elementand the rim of the upper face of the bit protrude above the face of thewood just enough to make an impression on the second piece of wood. Theextent of this protrusion is varied by adjustment of the collar,depending upon the hardness of the wood being marked. The chuck is thenun screwed from the bit, which remains in the hole. The second piece ofwood is then marked by bringing it into registration with the firstpiece, after which the bit is removed.

My device thus ensures the hole in the first piece being automaticallydrilled to the proper depth and eliminates the need for placing aseparate markingelement in the hole. This saves a great deal of time forthe operator.

Another important advantage of my invention is that the marking deviceis automatically set into the hole to the proper depth merely bydrilling the hole. There is no need for withdrawing the drill andinserting a separate marking ele ment in the hole, with the settling ofwood chips and wood dust in the bottom of the hole, resulting fromwithdrawal of the bit making it possible that the marking element willnot fit properly in the hole.

Other objects and advantages of my invention will become apparent fromthe following description, in conjunction with the annexed drawing, inwhich a preferred embodiment is shown.

In the drawing,

Fig. l is an exploded front view of my im proved combined drilling andmarking device, the collar for the chuck being shown in verticalsection;

Fig. 2 is a front view of the assembled drill, partly in verticalsection, showing the bit embedded in a hole in a first wood piece;

Fig. 3 is a view similar to Fig. 2 but showing the chuck removedpreparatory to marking a second wood piece;

Fig. i is a top plan View showing two drills embedded in the first woodpiece, with their chucks removed; and

Fig. 5 is a bottom plan view of the second wood piece after it has beenmarked by placing it upon the surface of the wood piece of Fig. 4.

Upon reference to the drawings in detail, it will be seen that they showa combined drilling and marking device comprising bit it, hit shank l I,chuck I2 and collar i3.

Shank ll has a cylindrical peripheral wall which has a spiral peripheralgroove 46 extending the entire length thereof. Bit it depends from shankH and is integral and coaxial therewith. Bit It hasthe usual threadedpoint l5 and the usual spiral cutting flutes M, with a spiral channelbetween flutes as which communicates with groove it to provide a pathfor the upward movement of shavings while a hole is being drilled.

Chuck I2 is separable from shank ll. Shank II has a recess [6 in its topface. The top face of shank ll is substantially cut away by said recessIt until only a substantially circular rim l9 remains. The upper edge ofrim it? serves as a marking edge and may optionally be sharpened. RecessI5 is substantially in the shape of an inverted frustro-cone.

Recess I6 is co-extensive at its lower end with an axially extending,cylindrical recess I1 which is closed at its lower end. The peripheralwall of recess I1 is threaded with screw-thread I9.

I provide a marking element 29 which has a cylindrical shank whose lowerend is embedded in shank II below recess I1. The shank of markingelement 20 extends axially upwardly through recess I1 into recess I6.Marking element 22 has a conical point 2| which is integral with the topof the shank thereof. Optionally and preferably, the apex of conicalpoint 2I is positioned slightly above the plane of cutting edge I9. Theapex of point 2| is located on the axis of shank I I.

Chuck I2 is of any suitable shape to fit within the jaws of thedrill-holder. Preferably, chuck i2 is substantially cylindrical inshape. Chuck 12 has a depending, co-axial screw portion 2?. of reduceddiameter, whose outer peripheral wall is preferably cylindrical and isthreaded. Chuck I2 and shank II may be assembled by screwing screwportion 22 into recess I'I, screw threads 23 and I8 being interfitting.The diameter of bit shank I I is slightly greater than the diameter ofchuck I2. Chuck screw 22 is screwed into recess I1 until the lowerperipheral edge of the body of chuck I2 abuts the peripheral wall ofrecess I1, as is clearly shown in Figs. 2 and 3. The threading I8extends below screw portion 22, so that the latter will not bind inrecess H1 and can be readily unscrewed. Optionally, other means forinterfitting extension 22 in recess I1 may be provided.

In order to receive marking element 29, chuck I2 has a co-axial,cylindrical recess 29 which extends upwardly from the bottom face ofscrew portion 22 and which is of greater diameter than marking element29. Recess 24 extends upwardly into the main portion of chuck I3 and istapered at its upper portion 25. When chuck I2 and shank II areassembled, the upper part of marking element 20 extends into recess 24,and tip 2I may extend into recess portion 25.

The depth of the hole drilled by bit I depends upon the mounting ofcollar I3 on chuck l2, collar I3 being axially adjustable on chuck I2.Collar I3 has a substantially cylindrical body portion 26 which isintegral at its lower end with a substantially cylindrical stop portion21 of increased diameter. Collar body 26 has a cylindrical, axiallyextending bore 28 which extends into stop portion 21 and communicateswith a recess 29 therein of increased diameter, said recess 29 extendingto the lower face of stop portion 21.

Collar I3 is mounted on chuck I2 with the latter extending slidably andturnably through recess 29 and bore 28. I provide a set-screw 3B whichextends through a suitably threaded, radially extending opening 3| inthe peripheral wall of collar body 26. Said screw 30 may be turned untilit frictionally abuts chuck I2, to lock collar IS in the desired axialposition with respect to chuck I2.

In order that rim I9 will extend above the hole drilled by bit III,recess 29 is of greater diameter than bit shank II, so that the lowerface of stop portion may extend below rim I9.

The operation of the device is as follows:

Collar I3 is mounted on chuck I2, and chuck I2 is screwed into bit shankII. The axial position of collar I3 relative to chuck I2 is such thatrim I9 and the tip of point 24 extend a slight distance above the lowerface of stop member 21, this distance depending upon the type of 4 woodto be marked and being generally greater for soft wood than for hardwood.

The assembled device is then mounted in a suitable holder, and a hole 32is drilled in a first piece of wood 33, said hole 32 being transverse tothe surface of piece 33. This is shown in Fig. 2. The drilling of hole32 continues until the lower face of stop member 21 abuts the face ofpiece 33.

In the drilling of hole 33, stop member 21 optionally serves to helpmaintain the drill transverse to the wood. The diameter of stop mem ber21 is relatively wide, and it is possible to maintain a horizontal lineof sight and to keep the lower face of stop member 21 within the line ofsight and hence parallel to the upper face of the wood. Since stopmember 21 is perpendicular to the axis of the drill, this ensures thedrilling of a transverse hole in the wood.

As the next step, chuck I2 is unscrewed from shank II, leaving thelatter in hole 32. This is shown in Fig. 4. As is also shown in Fig. 4,I can optionally employ more than one of the drills in order to make aplurality of holes, each containing a marking device, prior to markingthe second piece of wood.

Fig. 5 shows a second piece of wood 39, whose face has been forcedagainst the face of piece 33. As a result, point 2I and rim I9, whichextend above piece 33, cut a corresponding point 36 and circular groove35 in piece 34, which mark the place at which the hole inpiece 34corresponding to hole 32 may be drilled. Shank II is then removed fromhole 32.

While it is possible to eliminate marking element 20, or to make rim I9a non-marking rim, the arrangement shown in the drawing is preferred.Optionally, collar I3 may be fixed to chuck I2.

An important feature of the invention resides in the manner in whichcollar I3 may be adjusted upon chuck I2 in order to control the depth ofthe hole, whereby to control the extent to which marking rim I9 andpoint 2i 'extend above the surface of the wood. The extent of protrusionof the marking element from the finished hole depends upon the readilymeasured axial distance between the lower face of collar I3 and markingrim I9. In contrast, if a separate marking element is used, it has beenfound necessary in practice to drill the hole and insert the markingelement by trial and error, until the marking element protrudes abovethe hole to exactly the desired extent.

I have disclosed a preferred embodiment of my invention and haveindicated various changes, omissions and additions which may be madetherein. However, it will be apparent that various other changes,omissions and additions may be made in my invention without departingfrom the scope and spirit thereof.

I claim:

1. A drilling and marking device comprising a drill which has acylindrical shank and a bit depending from said shank, said shank havinga transverse face which has a shank recess whereby said face is in theform of a circular marking rim, the peripheral wall of said recesssloping inwardly, said shank recess communieating with a cylindrical,axially extending, screw-threaded recess, a cylindrical marking elementembedded in said shank below said threaded recess and extending upwardlythrough said recesses and being spaced from the peripheral wallsthereof, the free end of said marking element being tapered to provide apoint whose tip is positioned above and proximate to the plane of saidrim, a cylindrical chuck of smaller diameter than said shank which has adepending, cylindrical, axially extending, screw-threaded projection,the lower face of said projection having an axial recess therein, saidchuck and said shank being releasably engageable by screwing saidprojection into said threaded recess with said marking elementpositioned slidably and turnably in said projection recess and with thelower edge of the peripheral wall of said chuck abutting the peripheralwall of said shank recess, and a collar which has a cylindrical borethrough which said chuck extends slidably, said bore being of increaseddiameter at its lower end to fit around the peripheral wall of saidshank, said collar carrying means for releasably looking it on saidchuck with the lower face of said collar positioned below the plane ofsaid rim.

2. A drilling and marking device comprising a. bit, marking meanscarried by the upper end of said bit, a chuck, said chuck and said bitrespectively carrying means for releasably interengaging same, and astop member mounted on said chuck, said stop member having its lowestsurface extending radially beyond the periphery of said bit and alsoextending below the level of said marking means. Y

3. A drilling and marking device comprising a drill, said drillcomprising a cylindrical shank which has a depending bit, said shankhaving a transverse upper face which has a recess to form an annularmarking rim in said upper face, a chuck which has a. depending extensionwhich is of a size and shape to fit within said recess, means forreleasably retaining said extension within said recess, and a stopmember mounted on said chuck, said stopfmember having its lowest surfaceextending radially beyond said shank and also extending below the planeof said rim.

4. A device in accordance with claim 3, in which said shank has fapointed marking rod which extends upwardly in said shank recess, saidextension having aJrecess for receiving said marking rod when saidextension and said shank are engaged, the tip of said marking rod beingin approximately the same plane as said marking rim.

5. A device in accordance with claim 4, in which said stop membercomprises a collar having a bore through which said chuck extendsslidably, said collar having means for looking it to said chuck.

6. A device in accordance with claim 3, in which said stopmemberf'comprises a collar having a bore through which said chuckextends slidably, said collar having means for locking it to said chuck.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,092,653 Nielson Sept. 7, 1937 2,500,653 Berg Mar. 14, 19502,570,945 Hawkins Oct. 9, 1951

